This isn't the kind of old-style ambush, with a news crew surprising someone accused of wrongdoing and recording the response on camera. Every person on these new prank shows has agreed to be interviewed.

The difference is that most of these media-savvy "marks" don't realize, or know, that they're stepping into carefully planned setups intended to mock them and amuse audiences. (Related story: Candid Camera, the next generation

Experts, policymakers and influential movers and shakers are invited to be interviewed on serious issues. But after the cameras are rolling, the hosts surprise, befuddle and outrage them by asking inciteful, ignorant or inane questions.

The ambush interview itself isn't new. "Stuttering John" Melendez, for one, did this for years — stopping celebrities at red-carpet events and asking raunchy or ridiculous questions for audio interviews that aired on Howard Stern's radio show.

But today, as the spoofing spreads to more serious newsmakers, the fallout is a growing trail of disgruntled guests. Some say the shows are politically motivated by liberal comedians aiming to trap conservatives; others threaten lawsuits on the grounds of fraud.

Jim March, a lobbyist for the Citizens Committee for the Right to Keep and Bear Arms, says he was deceived when he was asked in May to appear on The Debate Show, now known as Crossballs: The Debate Show.

The contract stated that The Debate Show was a "tentative title" and that the show would air on a Viacom channel, without specifying Comedy Central. March was invited on to discuss gun rights. But, he says, the show became "one long, grotesque genitalia joke."

Matt Besser, a Crossballs executive producer who plays a fake expert on each show, posed the argument as an anti-gun advocate that guns are substitutes for a lack of sexual prowess.

" 'When was your first homoerotic experience?' That was question No. 2 or 3," March says.

"I am beyond furious," he says. He maintains that the show wasn't satire but a "personal attack."

March considered walking away during taping, he says, but had been paid $200 and put up in a hotel room and felt he should fulfill his obligation. In the end, he says, "they played me like a fiddle, very professionally."

And March says it was political. He says Besser "got what he figured was a right-winger — although I'm more libertarian than GOP — and thought, 'I'll bushwhack the bejesus out of him.' "

March's lawyer has sent a letter threatening legal action on the basis of fraud if the show airs. Comedy Central says March signed a release, and the channel is "confident it will hold up against his complaints."

David Logan, lawyer and dean of the Roger Williams University Law School in Bristol, R.I., says that if a release or waiver has been signed, it makes it difficult to sue. "It's entertainment, maybe low-brow entertainment. You're setting people up — ha-ha, practical joke. It's not intense cruelty. It doesn't go to the soul of the persona and their identity. It's sophomoric stuff."

Humiliation isn't grounds for damages, he says. "In most jurisdictions, the intentional infliction of severe emotional distress is wrong. But the keyword is severe. ... If it's just someone saying something sophomoric or unpleasant, that's probably not intentionally inflicting severe emotional distress. It's being embarrassed."

Or as the comedians would say: It's social satire.

'Deception' lands interviews

Ali G (real name Sacha Baron Cohen) attended the University of Cambridge. Although he has been a household name in Great Britain since 1998, Ali G only recently become known in the USA.

Cohen, who refused to be interviewed for this story because it wasn't solely about him, is the subject of a new Vanity Fair profile. He has "interviewed" famous folks including Newt Gingrich, Buzz Aldrin, Brent Scowcroft, Ralph Nader and Donald Trump.

According to Vanity Fair, Ali G "uses deception" to land the interviews, sending letters on fancy letterhead explaining that Ali G is the host of an educational program for youth, which is Cohen's way of looking at the show.

Donaldson says he remembers thinking, "Well, maybe this is a mod channel — their version of MTV or worse. Maybe he's popular with 14-year-olds in Britain."

Even when it was over, Donaldson didn't know quite what had happened. "I did not realize that I was being put on, if in fact it's a spoof and a gag and people like me are unwittingly playing a role. I thought it was crazy and gave serious answers." But he's a good sport about it: "If this is the worst thing that happens to me, I'm a star."

'Revolting' turn of events

As for any guilt or shame over mocking serious guests, Cohen doesn't clearly answer that, although the point made in Vanity Fair is that his comedy is intended to reveal injustices such as homophobia and class prejudice.

It's just that those being interviewed don't always find it amusing when it's happening.

"It was a completely revolting experience," says James Hanken, a Harvard zoology professor who was taken by Ali G several years ago. "He was just bizarre."

They sat in Hanken's Harvard office and Ali G began asking questions. "They were stupid and offensive in many respects," Hanken says. An example: "Why is all giraffes gay?"

"I almost threw him out. He was making derogatory comments about women and minorities. I was very uncomfortable."

Discomfort is part of a well-pulled-off prank.

"The best kind of comedy has a straight man, and a real person makes the best straight man," Besser says.

Like Cohen, Besser believes he's in the satire business. Crossballs describes itself as a "fake show" with "real experts," designed to be a blend of two expert-driven shows: CNN's Crossfire and MSNBC's Hardball With Chris Matthews.

Everyone on Crossballs is acting, arguing with the two real experts, one on each side of the table. The debates become outrageous, designed to goad the real experts, who tend to be passionate about their opinions.

Besser says he has no problems with setting up experts. "We're doing a good thing. Experts need to be held up to scrutiny. We do it to make comedy. I hope part of the satire is realizing this is what the other debate shows do as well. They don't say everything they're going to tell the guests."

Crossballs' guests, he adds, "get their opinion out. In the end, they can look silly for getting upset with us."

But some of Crossballs'guests — 48 experts in 24 shows already taped — say it's not at all what a real issues show would do. "The way the show is being promoted inside the industry is that it's trying to demonstrate how experts will do anything to get on television," says Lauren Weinstein, co-founder of People for Internet Responsibility, who was invited to the show to talk about spam.

"But what's been going on, in my experience, is that they call you up and start e-mailing and pushing and pushing, saying we're talking about important issues, you'll be helping young people. They play on your public spiritedness. So you say OK, fine, glad to help."

Weinstein has appeared many times on shows as an expert. As he researched The Debate Show, he realized he was walking into a trap and canceled hours before he was to appear. Nonetheless, he says, he and other experts who have done the show have been burned.

"You put yourself on the line. It does cut to your faith when you have someone out-and-out lie to you — or hold back" the real truth of the show, he says.

The Daily Show With Jon Stewart doesn't bill itself as a real news show, yet studies have shown many viewers tune in to get their news from it, further evidence of the blurring line between what's real and what's not on television.

Part of the show features taped goofy interviews with experts, much like Ali G or Crossballs. The difference is that The Daily Show is upfront about presenting itself as with Comedy Central, a good clue to its intention.

Rob Corddry, senior correspondent, does many of the setup interviews and says that the key is making the situation seem real.

"It's all about what question to ask when, and to sort of lull them into a false sense of security, then yell 'Boo!' Or to just present an odd premise to them with the straightest face possible so they actually consider it," he says.

And Corddry says he, like Ali G, is often the one looking silly.

"In the end, I'm usually the jackass. I'm only happy to play that role. We're not out to change anybody's mind or affect anything. We're only out to get a laugh."